1. Field of the Invention
The present invention relates to a wavelength selection switch.
2. Description of the Related Art
Jpn. Pat. Appln. KOKAI Publication No. 2005-91910 discloses a wavelength selection switch. This wavelength selection switch comprises a grating that spectrally separates entering light, a focusing optical system that receives the light spectrally separated by the grating and focuses the light at a predetermined position, a MEMS module that is arranged at the predetermined position and deflects the light entering through the focusing optical system, and a base on which the grating and the focusing optical system are mounted. The wavelength selection switch is an optical switch that switches the transmission paths of a wavelength-multiplexed optical signal for each wavelength.
The respective optical components such as the MEMS module are arranged on the base at positions determined in design. More specifically, screw holes formed in the respective optical components are matched to holes formed in the base. After that, screws are inserted in the holes of the base and screwed into the screw holes of the optical components to fix the respective optical components to the base.
In the conventional wavelength selection switch, however, a manufacturing error of the grating, the aberration of the focusing optical system, and the like undesirably shift the optical position of the grating or the focusing optical system from that of the MEMS module. Then, the intensity of the output signal light attenuates.
As a method of solving this problem, the screws may be temporarily loosened, and the positions of the respective optical components may be adjusted. With this method, however, accurate adjustment is impossible.